Technologies that are in development and not being deployed include the following:
- most energy storage (except for pumped hydro),
- generation of hydrogen from electrolysis
- redundant long distance transmission within the current grid to enable transfer of intermittent power across regions,
- control systems that monitor and control the long distance distribution of intermittent energy across large regions
So getting back to the theme of limits to renewables penetration, its clear that only as the problem is becoming real, is there some focus on how the problem can be solved. We are in the very early stages of recognizing the problem. This NREL study and the more academic and theoretical Solutions Project highlight how a centralized monitoring and control system is an essential part of a solution. This, in many ways would seem a bigger problem than developing and deploying energy storage, in large part because there is a big political problem as well as a big technical problem.
The NREL study only contemplates 30% penetration and relies on significant new technology not yet developed. The solutions project relies on even more technology not yet developed and is a more simplistic model that does not model an actual interconnect. These studies at least are starting to outline the problem as opposed to ignoring it as has been the attitude so far.
As I have previously maintained, the problems with renewables penetration need to be accepted before alternative solutions are evaluated. At this stage all the technologies being investigated or developed are very far from significant deployment. When viewed from this perspective, StratoSolar is no farther from deployment and no more speculative than the technologies being contemplated by these investigations. StratoSolar specifically addresses the daytime intermittency, nighttime storage, long distance transmission and cost of generation that will limit the future penetration of current PV solar and wind generation. Its cost of development is low. The timeframe to deployment if proven is long before 2026.
By Edmund Kelly